private void drawJoint(Joint joint) {
Body bodyA = joint.getBodyA();
Body bodyB = joint.getBodyB();
Transform xf1 = bodyA.getTransform();
Transform xf2 = bodyB.getTransform();
Vec2 x1 = xf1.p;
Vec2 x2 = xf2.p;
Vec2 p1 = pool.popVec2();
Vec2 p2 = pool.popVec2();
joint.getAnchorA(p1);
joint.getAnchorB(p2);
color.set(0.5f, 0.8f, 0.8f);
switch (joint.getType()) {
// TODO djm write after writing joints
case DISTANCE:
m_debugDraw.drawSegment(p1, p2, color);
break;
case PULLEY:
{
PulleyJoint pulley = (PulleyJoint) joint;
Vec2 s1 = pulley.getGroundAnchorA();
Vec2 s2 = pulley.getGroundAnchorB();
m_debugDraw.drawSegment(s1, p1, color);
m_debugDraw.drawSegment(s2, p2, color);
m_debugDraw.drawSegment(s1, s2, color);
}
break;
case CONSTANT_VOLUME:
case MOUSE:
// don't draw this
break;
default:
m_debugDraw.drawSegment(x1, p1, color);
m_debugDraw.drawSegment(p1, p2, color);
m_debugDraw.drawSegment(x2, p2, color);
}
pool.pushVec2(2);
}
@Override
public void solveVelocityConstraints(TimeStep step) {
Body b = m_bodyB;
Vec2 r = pool.popVec2();
r.set(m_localAnchor).subLocal(b.getLocalCenter());
Mat22.mulToOut(b.getTransform().R, r, r);
// Cdot = v + cross(w, r)
Vec2 Cdot = pool.popVec2();
Vec2.crossToOut(b.m_angularVelocity, r, Cdot);
Cdot.addLocal(b.m_linearVelocity);
Vec2 impulse = pool.popVec2();
Vec2 temp = pool.popVec2();
// Mul(m_mass, -(Cdot + m_beta * m_C + m_gamma * m_impulse));
impulse.set(m_C).mulLocal(m_beta);
temp.set(m_impulse).mulLocal(m_gamma);
temp.addLocal(impulse).addLocal(Cdot).mulLocal(-1);
Mat22.mulToOut(m_mass, temp, impulse);
Vec2 oldImpulse = temp;
oldImpulse.set(m_impulse);
m_impulse.addLocal(impulse);
float maxImpulse = step.dt * m_maxForce;
if (m_impulse.lengthSquared() > maxImpulse * maxImpulse) {
m_impulse.mulLocal(maxImpulse / m_impulse.length());
}
impulse.set(m_impulse).subLocal(oldImpulse);
// pooling
oldImpulse.set(impulse).mulLocal(b.m_invMass);
b.m_linearVelocity.addLocal(oldImpulse);
b.m_angularVelocity += b.m_invI * Vec2.cross(r, impulse);
pool.pushVec2(4);
}
/** Call this to draw shapes and other debug draw data. */
public void drawDebugData() {
if (m_debugDraw == null) {
return;
}
int flags = m_debugDraw.getFlags();
if ((flags & DebugDraw.e_shapeBit) == DebugDraw.e_shapeBit) {
for (Body b = m_bodyList; b != null; b = b.getNext()) {
xf.set(b.getTransform());
for (Fixture f = b.getFixtureList(); f != null; f = f.getNext()) {
if (b.isActive() == false) {
color.set(0.5f, 0.5f, 0.3f);
drawShape(f, xf, color);
} else if (b.getType() == BodyType.STATIC) {
color.set(0.5f, 0.9f, 0.3f);
drawShape(f, xf, color);
} else if (b.getType() == BodyType.KINEMATIC) {
color.set(0.5f, 0.5f, 0.9f);
drawShape(f, xf, color);
} else if (b.isAwake() == false) {
color.set(0.5f, 0.5f, 0.5f);
drawShape(f, xf, color);
} else {
color.set(0.9f, 0.7f, 0.7f);
drawShape(f, xf, color);
}
}
}
}
if ((flags & DebugDraw.e_jointBit) == DebugDraw.e_jointBit) {
for (Joint j = m_jointList; j != null; j = j.getNext()) {
drawJoint(j);
}
}
if ((flags & DebugDraw.e_pairBit) == DebugDraw.e_pairBit) {
color.set(0.3f, 0.9f, 0.9f);
for (Contact c = m_contactManager.m_contactList; c != null; c = c.getNext()) {
// Fixture fixtureA = c.getFixtureA();
// Fixture fixtureB = c.getFixtureB();
//
// fixtureA.getAABB(childIndex).getCenterToOut(cA);
// fixtureB.getAABB().getCenterToOut(cB);
//
// m_debugDraw.drawSegment(cA, cB, color);
}
}
if ((flags & DebugDraw.e_aabbBit) == DebugDraw.e_aabbBit) {
color.set(0.9f, 0.3f, 0.9f);
for (Body b = m_bodyList; b != null; b = b.getNext()) {
if (b.isActive() == false) {
continue;
}
for (Fixture f = b.getFixtureList(); f != null; f = f.getNext()) {
for (int i = 0; i < f.m_proxyCount; ++i) {
FixtureProxy proxy = f.m_proxies[i];
AABB aabb = m_contactManager.m_broadPhase.getFatAABB(proxy.proxyId);
Vec2[] vs = avs.get(4);
vs[0].set(aabb.lowerBound.x, aabb.lowerBound.y);
vs[1].set(aabb.upperBound.x, aabb.lowerBound.y);
vs[2].set(aabb.upperBound.x, aabb.upperBound.y);
vs[3].set(aabb.lowerBound.x, aabb.upperBound.y);
m_debugDraw.drawPolygon(vs, 4, color);
}
}
}
}
if ((flags & DebugDraw.e_centerOfMassBit) == DebugDraw.e_centerOfMassBit) {
for (Body b = m_bodyList; b != null; b = b.getNext()) {
xf.set(b.getTransform());
xf.p.set(b.getWorldCenter());
m_debugDraw.drawTransform(xf);
}
}
if ((flags & DebugDraw.e_dynamicTreeBit) == DebugDraw.e_dynamicTreeBit) {
m_contactManager.m_broadPhase.drawTree(m_debugDraw);
}
}
@Override
public void initVelocityConstraints(TimeStep step) {
Body b = m_bodyB;
float mass = b.getMass();
// Frequency
float omega = 2.0f * MathUtils.PI * m_frequencyHz;
// Damping coefficient
float d = 2.0f * mass * m_dampingRatio * omega;
// Spring stiffness
float k = mass * (omega * omega);
// magic formulas
// gamma has units of inverse mass.
// beta has units of inverse time.
assert (d + step.dt * k > Settings.EPSILON);
m_gamma = step.dt * (d + step.dt * k);
if (m_gamma != 0.0f) {
m_gamma = 1.0f / m_gamma;
}
m_beta = step.dt * k * m_gamma;
Vec2 r = pool.popVec2();
// Compute the effective mass matrix.
// Vec2 r = Mul(b.getTransform().R, m_localAnchor - b.getLocalCenter());
r.set(m_localAnchor).subLocal(b.getLocalCenter());
Mat22.mulToOut(b.getTransform().R, r, r);
// K = [(1/m1 + 1/m2) * eye(2) - skew(r1) * invI1 * skew(r1) - skew(r2) * invI2 * skew(r2)]
// = [1/m1+1/m2 0 ] + invI1 * [r1.y*r1.y -r1.x*r1.y] + invI2 * [r1.y*r1.y
// -r1.x*r1.y]
// [ 0 1/m1+1/m2] [-r1.x*r1.y r1.x*r1.x] [-r1.x*r1.y
// r1.x*r1.x]
float invMass = b.m_invMass;
float invI = b.m_invI;
Mat22 K1 = pool.popMat22();
K1.m11 = invMass;
K1.m21 = 0.0f;
K1.m12 = 0.0f;
K1.m22 = invMass;
Mat22 K2 = pool.popMat22();
K2.m11 = invI * r.y * r.y;
K2.m21 = -invI * r.x * r.y;
K2.m12 = -invI * r.x * r.y;
K2.m22 = invI * r.x * r.x;
Mat22 K = pool.popMat22();
K.set(K1).addLocal(K2);
K.m11 += m_gamma;
K.m22 += m_gamma;
K.invertToOut(m_mass);
m_C.set(b.m_sweep.c).addLocal(r).subLocal(m_target);
// Cheat with some damping
b.m_angularVelocity *= 0.98f;
// Warm starting.
m_impulse.mulLocal(step.dtRatio);
// pool
Vec2 temp = pool.popVec2();
temp.set(m_impulse).mulLocal(invMass);
b.m_linearVelocity.addLocal(temp);
b.m_angularVelocity += invI * Vec2.cross(r, m_impulse);
pool.pushVec2(2);
pool.pushMat22(3);
}
/**
* Compute the distance from this fixture.
*
* @param p a point in world coordinates.
* @return distance
*/
public float computeDistance(Vec2 p, int childIndex, Vec2 normalOut) {
return m_shape.computeDistanceToOut(m_body.getTransform(), p, childIndex, normalOut);
}
